A Gnu headed penguin "Powered by GNU/Linux" in 4K 3840x2160.
The original vector graphic image file is also included to edit/resize/export when needed. I recommend inkscape program for editing color, size and then export to png or other format.
The svg can be used for *any* resolution at least on KDE Plasma, not sure if other Desktops allow to set an svg image as wallpaper.